ABC | Volume 110, Nº4, April 2018

Original Article Dong et al Comparison between HCR and OPCAB Arq Bras Cardiol. 2018; 110(4):321-330 descending (LAD) coronary artery with drug-eluting stents (DES) to non-LAD target coronary arteries. Several studies have proved the excellent postoperative survival (higher than 99%) and LIMA patency rates (higher than 95%) of HCR, suggesting HCR should be considered as an alternative approach for patients with multivessel CAD. 10 A study in France confirmed the feasibility and safety of HCR and also detected that HCR compared favorably to those with traditional CABG alone. 11 In addition, both of simultaneous and staged HCR were indicated to be efficient and feasible with favorable outcomes at more than 12-month follow-up. 12,13 However, a 1-year clinical follow-up study angiographically showed a high rate of repeat revascularization after HCR. 14 In addition, a transient reduction in the antiplatelet effect of aspirin and clopidogrel was observed after HCR despite limited surgical trauma and off-pump technique. 15 Neither baseline platelet aggregation nor postoperatively increased platelet turnover and acute‑phase response could explain it. Therefore, further research is badly needed. Currently, several comparative studies about the clinical outcomes of OPCAB and HCR are available. Nonetheless, the optimal surgical strategy remains disputable. In the present analysis, we sought to compare the short-term and mid-term clinical outcomes of HCR versus OPCAB for the treatment of multivessel or left main CAD with a pooled data. Methods Search strategy and selection criteria We searched four electronic bibliographic databases including PubMed, EMBASE, Web of Science and Cochrane by using following keywords with different combinations: “coronary artery disease”, “multivessel coronary artery disease”, “left main coronary artery disease”, “no-touch coronary artery bypass”, “off-pump coronary artery bypass”, “hybrid coronary revascularization”, “minimally invasive coronary artery bypass” and “percutaneous coronary intervention”. The searches were limited to human studies and English-language literatures only. The last search date was March 1, 2017. Inclusion criteria were: (1) RCTs, cohort studies or case‑control trials (CCT) comparing the outcomes of HCR and OPCAB; (2) at least 15 participants in each group; (3) available to get complete data. In addition, exclusion criteria were: (1) duplicated papers that fail to provide supplementary information; (2) unfinished studies or unavailable data (3) studies with obvious defects in design or data statistics. Two researchers selected literatures and any disagreements were resolved through consensus. Data extraction and quality assessment For articles approved in the primary selection, two reviewers assessed the quality of studies and extract data independently. The CONSORT statement 16 and STROBE statement 17 were used to measure the quality of RCTs and observational studies, respectively. Low-quality studies should be excluded and any disagreements were resolved by consensus or judged by the senior author. Extracted information included: (1) characteristics of studies and patients; (2) basic management of HCR and OPCAB; (3) short-term (in-hospital or 30-day) and mid-term (3 months to 36 months) mortality, stroke and major adverse cardiac and cerebrovascular event (MACCE) which was defined as the incidence of all-cause death, stroke, myocardial infarction (MI) and target vessel revascularization (TVR); (4) in-hospital outcomes: operation time, ventilator time, ICU stay, hospital stay, blood transfusion rate, incidence of atrial fibrillation (AF) and hospitalization costs. Statistical analysis We performed the analyses using RevMan 5.3 software (Cochrane Collaboration, Copenhagen, Denmark). Relative risk (RR) with 95% confidence interval (CI) was calculated for dichotomous variables and standardized mean difference (SMD) with 95% CI was calculated for continuous variables. Then Forest plots were presented graphically for all clinical outcomes. Statistical heterogeneity between studies was calculated using chi-squared test and the I -squared measure on a scale of 0-100% (less than 50% represented a low heterogeneity, 50%-75% indicated a moderate inconsistency and higher than 75% meant a large degree of heterogeneity). Fix-effect model was used in analysis with heterogeneity < 50% while random-effect model was conducted with heterogeneity ≥ 50%. In addition, publication bias of short‑term (in-hospital or 30-day) MACCE rate was also assessed using funnel plot. Two-sided p value < 0.05 was considered statistically significant. Results Literature selection and characteristics of studies The process of literature selection for potentially eligible studies and exclusion reasons is illustrated using a flow diagram in Figure 1. Initially, 1045 published articles were identified (455 from PubMed, 469 from EMBASE, 106 from Web of Science and 15 from Cochrane). Overall, 52 unduplicated English articles related to HCR and OPCAB were selected from these citations. Finally, nine observational studies with 6121 patients were included in the present analysis. 18-26 The basic characteristics of these studies are presented in Table 1. Among 6121 patients, 5418 (88.5%) subjects got OPCAB while 290 (4.7%) patients received staged HCR and 398 (6.7%) patients received simultaneous HCR. For those who underwent HCR, minimal invasive techniques such as endoscopic atraumatic coronary artery bypass (endo-ACAB), mini-sternotomy and mini-thoracotomy were utilized. Most of them received DES and a combination of aspirin and clopidogrel was applied as a preventive antiplatelet therapy. Short-term (in-hospital or 30-day) and mid-term clinical outcomes are shown in Table 2. Short-term outcomes As illustrated in Table 3, there was no significant difference in short-term MACCE rate (relative risk (RR): 0.55, 95% confidence interval (CI): 0.30–1.03, p = 0.06; p 322